Minutes and 4 seconds. How many hours in the days

Most We are developing common concepts in early childhood. Despite the age of integrity, it is unlikely that any of the kids require an academic explanation for the most simple concepts - Mom can explain everything literally on the fingers, simple words. For example, "Day is when the sun shines" or "when you walk, and not sleep in the crib." Explanations are imperceptibly accumulated and systematized by forming an understanding of the term.

The meaning of the word "day"

If you look at the planet from the side, you can see quite clear separation on the day and night side. Formally, the simplest explanation is faithful from the point of view of astronomy - the day is considered to be when the light from the star falls on the surface of the planet, around which this planet rotates.

We believe that the day is a bright day of day, and the weather does not play roles. Somewhere there, above the clouds, the sun still shines, therefore, no night, around is not dark. In the same latitudes, this particular principle is observed - such concepts as a "polar day" and "polar night" are based on natural illumination.

In some cases, I mean time at all. For example, when they say "these were sad days" or "in those distant days", we are talking about some distant time in the past, when there were some events.

Division of day

Theoretically, if you rely precisely for the presence of the sun in the sky, the day is divided into two relatively equal parts - day and night. In practice, it turns out that there are morning and evening, which in one degree or another are also highlighted. Morning begins when the scan of the approaching sun appears in the sky, although the night continues formally. When the sun appears above the horizon, the dawn begins, the morning continues and lasts a few more hours while the sun rises to Zenith.

In most cases, the day is the time from about noon to the evening, when the sun begins to decline over the horizon in the West. At the same time they say "ten o'clock in the morning", but "eleven hours of the day", and even in this case options are possible.

How many hours do the day last?

Between the morning and in the evening passes on average six hours, and this is an approximate time. It turns out that day is the whole fourth part of the day. The rest of the time is occupied at night and intermediate states - in the morning and evening.

If the clarifying adjective is added to this, it becomes easier to determine what it is specifically a question. For example, a "light day" clearly indicates that we are talking about the light of the day of day when the additional sources of artificial lighting are not required. Explaining what day is, it is desirable to immediately arrange accents and clarify that much depends on the specific situation and context, otherwise mutual misunderstanding may appear.

Often the length of the day is determined not by the actual number of hours and not durability natural lighting, and extremely subjective sensations. A long or even endless day means that either a person cannot wait for the evening, or managed to perform many different tasks.

Specification of temporary intervals

Often the word "day" is used in the meaning of the "day". For example, "you have three days to eliminate the shortcomings." In the "day" value, this word is used when you need to specify a sufficiently long amount of time.

If you want to put some framework, it can be a "working day" - interpretation in this case provides that weekends and holidays are not considered. In working days, business commitments are taken into account - the execution of orders, the receipt of funds to the bank account and so on. The obsolete concept of "workshop" is similar to the value, this is a unit of collective farmers' work for subsequent payment. When they say "day off," they mean a day free from all kinds labor duties, Time designed to relax.

Trying to understand what day in the presentation of another person, we usually try to simplify mutual communication as much as possible. Therefore, when we are told "Call tomorrow day," it is better to clarify, at what time interval will be appropriate. For someone and eight o'clock in the morning - the day, and someone else sleeps. If you do not specify, then business etiquette The day is considered an average of 11 am to 16 in the afternoon, and a good tone will fit around in about the middle of this gap. In other cases, it is better to ask to specify the exact time.

Time is the most important philosophical, scientific and practical category. The choice of a method for measuring time was interested in a person from ancient times when practical life It began to communicate with the conversion periods of the Sun and the Moon. Despite the fact that the first hours are sunny - appeared for three and a half millennium BC, this problem remains quite complicated. Often answered the easiest question, with it connected, for example, "how many hours in the days", it is not so simple.

History of the study

The alternation of the light and dark time of day, periods of sleep and wakefulness, work and recreation began to mean for people the course of time even in primitive times. Daily the sun was moving around the sky during the day, from sunrise to sunset, and the moon - at night. It is logical that the period between the same phases of the movement of the movement became the unit of the presentation. Day and night gradually developed in a day - the concept determining the shift of the date. On their basis, more brief units of time appeared - hours, minutes and seconds.

For the first time determine how many hours in the days of the clock, steel in ancient times. The development of knowledge in astronomy led to the fact that the day and night began to share on equal periods associated with the sunrise to the celestial equator of certain constellations. And the sixflueder system of surgery of the Greeks was adopted from the ancient Suchmers who considered it the most practical.

Why exactly 60 minutes and 24 hours?

To count something ancient man Used what is usually always at hand - fingers. From here takes the beginning a decimal number system adopted in most countries. Another way based on the phalanges of the four fingers revealed the palm of the left hand, reached a heyday in Egypt and Babylon. In the culture and science of the Sumerians and other peoples of Meternrech, the sacred was the number 60. In many cases, to share it without a residue allowed the presence of many divisors, one of which is 12.

The mathematical concept of how much hours in the days of the clock, originates in Ancient Greece. The Greeks at one time took into account the calendar only the bright time of the day and divided the time from sunrise to sunset for twelve equal intervals. Then they also arrived at night, as a result, a 24-bed division of the day was obtained. Greek scientists knew that the longitude of the day was changing during the year, so for a long time there were daily and night hours, which were the same only in the days of equinox.

The Greek Sumerians were perceived by the division of a 360 degree circumference, on the basis of which a system of geographic coordinates was developed and an hour division for a minute (Minuta Prima (Lat.) - "Reduced first part" (hour)) and seconds (Secunda Divisio (Lat.) - "Second division" (hour)).

Sunny day

The meaning of the day relative to the interaction of heavenly objects is a period of time for which the land makes a complete turn around the axis of rotation. Astronomic scientists take several clarifications. They highlight sunny day - The beginning and end of the turnover is considered to find the Sun in the same point of the heavenly sphere - and share them to true and medium.

To say up to a second, how many hours in the days, which are called true sunny, without specifying a specific date is impossible. During the year, their duration varies periodically for almost a minute. This is due to the non-uniformity and the complex trajectory of the movement of the light on the celestial sphere - the axis of rotation of the planet has a slope of about 23 degrees relative to the plane of the celestial equator.

More or less accurately can be said how many hours and minutes in the days, which specialists are referred to as medium sunny. This is the usual used in everyday life Calendar segments of time defining a specific date. It is believed that their duration is constant, which is in them exactly 24 hours, or 1440 minutes, or 86,400 seconds. But this statement is conditional. It is known that the speed of rotation of the Earth decreases (the day is lengthened in a hundred years at 0.0017 seconds). The intensity of rotation of the planet is affected by complex gravitational cosmic interactions and spontaneous geological processes Inside it.

Starday

Modern requirements for calculations in space ballistics, navigation, etc. These are the question of how many hours a day lasts, requires a solution with an accuracy of nanoseconds. For this, more stable reference points are selected than nearby celebrity bodies. If you calculate full turn globeBy taking its position in the original moment relative to the point of spring equinox, it is possible to obtain the duration of the day called star.

Modern science accurately establishes how many hours in days wearing the beautiful name of the star, - 23 h 56 min 4 s. In this case, in some cases, their duration is even more specified: the true number of seconds is 4,0905308333. But this scale of clarifications is insufficient: the unevenness of the orbital movement of the planet affects the constancy of the reference point. To exclude this factor, a special, ephemeride origin coordinates associated with extragalactic radio sources is selected.

Time and calendar

The final version of the definition of how many hours in the days, close to modern, was adopted in ancient Rome, with the introduction of the Julian calendar. Unlike an ancient Greek system, the day of day was divided into 24 equal intervals, regardless of the time of day and season.

In different cultures, their calendars are used, having a point of reference specific events most often of a religious nature. But the duration of the average sunny day throughout the Earth is the same.

This is all known - 24 hours. But why did it happen? Let's consider in more detail the history of the appearance of the main units of time measurement and find out how many hours in the days of hours, seconds and minutes. And also look, whether it is worth binding these units exclusively to astronomical phenomena.

Where did the day come from? This is the time of one turnover of the Earth around its axis. There is still little that knowing about astronomy, people began to measure the time with such ranges, including each bright and dark.

But there is interesting feature. When do the day begin? From a modern point of view, everything is obvious - a day begin at midnight. People of ancient civilizations considered otherwise. It is enough to look at the very beginning of the Bible, so that in the 1st book of Genesis to read: "... And there was evening, and there was one morning." The day began with this there is a specific logic. The then people focused on the sun village, the day ended. Evening and night is the next day.

But how many hours in the days? Why did the day divided for 24 hours, because there is more conveniently a system system, and much? It would be in days, let's say 10 o'clock, and in every hour 100 minutes, would something change for us? Actually, nothing but numbers, on the contrary, would even be more convenient to make calculations. But a decodent system is far from the only one used in the world.

In used sixties. And the bright half of the day was well divided in half, 6 hours each. Total in the days turned 24 hours. This is quite a convenient division of Babylonians and other peoples.

Ancient Romans counting time occurred even more interesting. The countdown began from 6 am. So they believed from this moment further - the first hour, the third hour. Thus, it is easy to calculate that the "Eleventh-hour employees" are commemorated by Christ are those who begin to work at five o'clock in the evening. Indeed, late!

At six o'clock in the evening, the twelfth hour was assumed. That's how many hours in the days numbered in ancient Rome. But there was still no night hours! The Romans did not forget about them. After the twelfth hour, night guards began. The duty replaced at night every 3 hours. Evening and night time was divided into 4 guards. The first evening guard started at 6 o'clock in the evening and lasted to 9. The second, midnight, lasted from 9 to 12 hours. The third guard, from 12 nights to 3 am, ended when the roosters sang, therefore it was called - "singing of the roosters." The last, fourth guard, was called "Morning" and ended at 6 am. And it all started at first.

The need to share composite parts also the clock has arisen much later, but they have not retreated from the sixties. And then and the minute was divided for seconds. True, it later turned out that it was impossible to rely only on to determine the duration of seconds and the day. By a century, the duration of the day increases by 0.0023 seconds - it seems to be quite small, but enough to get confused on how many seconds in the days. And that's not all the difficulties! One turn around the Sun Our land does not make a permanent amount of day, and this also affects the solution of the question of how many hours in the days of the clock.

Therefore, to simplify the situation, a second was equated to movement heavenly Tel, and by the time of flowing processes within the Cesium-133 atom in rest. And to match the actual state of affairs with the turnover of the Earth around the Sun, twice a year - December 31 and June 30 - add 2 extra leapsday seconds, and once every 4 years - extra day.

It turns out that in the days of 24 hours, or 1440 minutes, or 86400 seconds.

How many last day?

If you take a distant star for the reference point, and for days to consider the gap for which it will return to the same point, it turns out that one turnover of our planet takes 23 hours 56 minutes and 4 seconds! That is, in the day, the astronomical midnight can wage almost 4 minutes! Moreover, this period is called by stellar days depending on the friction caused by synoptic situations, tides / lowers and geological events change all the time in the range of up to 50 seconds. If you take our sun for reference point, as the ancestors did, then the number is already obtained closer to 24 hours. This is called the sunny day. On average, for the year, taking into account the turnover of the planet around the Sun, the sunny day for a split second in short, than twenty-four hours.

When these discrepancies revealed with the help of the most accurate atomic hours, it was decided to override a second as a fixed share of the "sunny" day, more precisely, a million-scenes-forty-fading.

The new second was in use in 1967 and was defined as "time interval equal to 9,192,631,770 radiation periods corresponding to the transition between two ultra-thin levels of the main state of the cesium atom-133 in the absence of perturbation by external fields." More precisely, you can not say - it is only painful to disappear all this at the end of a long day.

The new definition of a second means that the sunny day is gradually shifted in relation to atomic. As a result, scientists had to be introduced into the atomic year the so-called "leap second" (or "second coordination") in order to coordinate atomic year with sunny.

From 1972, a leap second was added 23 times. Imagine, otherwise, our days would have increased almost half a minute. And the land continues to slow down its rotation. And, according to scientists, in the XXIII century, in our days there will be 25th hours.

The last time the "leap second" was added on December 31, 2005 to indicate the International Service for Establishing the Rotation Parameters and the Earth Coordinates Based in the Paris Observatory.

Good news for astronomers and those of us who love when the clock go pace with the movement of the Earth around the Sun, but a headache for computer programs and all the equipment that stands on space satellites.

The idea of \u200b\u200bentering a "leap second" met a decisive confusion from International Union Telecommunications, who even made an official proposal to completely cancel it in December 2007.

You can, of course, wait until the difference between universal coordinated time (UTC) and middle time in Greenwich (GMT) reaches exactly an hour (somewhere after 400 years) and then put everything in order. But as long as the debate around what is considered "real" time, continues.

Earth days - This is the time for which the land turns around its axis, and the "Day-Night" cycle is shown. Our life is subordinated to this cycle. In the morning we go to work, go to bed in the evening. Relevant cyclic physiological processes in living organisms got a name biological rhythms (biorhythms). For example, minimum temperature The people have a lot of bodies in the morning, and the maximum in the evening. With severe purulent infections, the temperature difference in the morning and in the evening reaches 3-4 degrees Celsius.

It seems to me that for most urban people 24-hour biorhythm is imposed and violent, Proof of which is the regular use of alarm clock. Nevertheless, you can accustom yourself to go to bed and get up at the same time of the day. If our day is lengthened (for example, the autumn translation of the clock shooter), it is moved easier than when it shortening in the spring, when you have to get up an hour earlier.

How many hours a day will last in a person who lives "out of time", that is, not having any opportunity to determine the time of day external signs? These multi-month experiments, including themselves, describes french speleologist (from Greek. Spelaion - Cave) in his book " In the abnumbs of land", Published in Moscow in 1982. Of course, the material below cannot be considered an exhaustive overview of the accumulated global experience in biorhythmology, it is only a curious information for reflection.

The experiments described in the book were conducted from 1964 to 1972 in deep caves At the border of Italy and France, as well as in the United States. Caves are comfortable in their own permanent climatic conditions : silence, complete absence of wind and sunlight, constant temperature and humidity. Experimental speller spellings participated in the executions. Cave is a more natural natural environment, full of dangers (abdain, cold, dampness, darkness, rare insects and even mice) compared to a specially built bunker.

Why did it need it? Not only for the sake of "bare" science. In the 1960s, space was actively mastered, many years of expeditions were planned to other planets, and NASA was interested in long-term experiments on the influence of the insulation of people on their livelihoods. The results of the experiments even became interested in the French military department. Why is interested in - learn below.

Is it easy to live in a cave months? Not. If you are able to communicate with anyone for 2-3 days, without suffering from the shortage of communication, then you may have happened. IN free time Speletologists read books (everyone had artificial lighting), hobbies were engaged in (drawing, photography), investigated their cave. But every day they had a whole list of boring mandatory cases: calls "Top" about each event (awakening, eating, physiological shipments, waste), a number of annoying psycho-physiological tests for the collaboration, employment, speed of reaction, etc. In addition, in a number of experiments I had to constantly wear sensorsWhich in those days were not always portable, so volunteers were in a cave, like dogs on taking a few meters. And the electrodes of sensors irritated the skin. Every day I had to collect and send to the top urine and feces analyzes. It was even analyzed by the composition of the stratified bristles. Speleologists led in caves diarywhere they recorded a subjective date and their feelings. The real date knew only at the top of the maintenance team. These long-term experiments did not always have enough money, but all participants held very hard, despite the difficulties. From a lack of money for food during the experiment in the US, the accompaniment group even caught and eaten rattle snakes.

Brief results of the experiments "out of time"

1) in 1964-1965 Parallel individual experiments took place Antoine Senny (4 months old, man 35 years old) and (3 months, woman 25 years old). In those days, such a duration of a single stay in the cave was an unattainable record, especially among women.

Antoine Senny (Tony):

• when Tony considered out loud to 120 in order to subjectively, measure the interval in 2 minutes, actually passed from 3 to 4 minutes.

From the first month of the experiment, a violation of the rhythm of wakefulness and sleep at Antoine Senny was discovered. Its day sometimes lasted 30 hours in a row, and the duration of sleep several times exceeded 20 hours. This gave a reason for concern.

Especially he struck us when for 22 days the duration of its day varied from 42 to 50 hours (on average 48 hours), with fantastically long periods of continuous activity - from 25 to 45 hours (on average 34 hours) and with a duration of sleep from 7 to 20 hours. We discovered the phenomenon called by us in 1966 two-day rhythm, that is, about 48 hours duration.

On the 61st day of this exceptional experiment, Tony made us seriously pass through: he slept 33 hours. I was already afraid for his life and was preparing to go down to him, how suddenly he was heard phone call: Tony reported to me that I spent the night well!

So, the average duration sleep Tony at 48-hour rhythm was 12 o'clock. Its daily cycle consisted of 36 hours of wakefulness and 12 hours of sleep, but this pattern was broken several times: Senny could sleep for 30 hours, and then only 18 hours remained at the active period. Therefore, in 1965 military Ministry France It was decided to study in more detail the nature of this sleep, which so significantly increases the human performance and gives the body a huge opportunity to restore forces. Such experiments were held in 1968-1969 (hereinafter referred to as this page, see Experience No. 3).

2) in 1966. Recorded experiment passed Jean Pierre Meret - "Human laboratory" (6 months).
This volunteer had perhaps the most difficult. He lived almost all the time with sensors, which registered the electrical activity of its brain, eye movement, muscle tone, heart and respiration rhythms, body temperature and leather. Electrodes irritated to the skin up to the bleeding, but they sake themselves "to suffer some more" for science every time, and he agreed every time.

Meret woke up and went to bed every day two to three hours later than the previous day. In this study, with the help of electroencephalograms registered during sleep, the presence of the test 48-hour biorhythm.

During the first 10 days of life in a cave, daily rhythm in Meret was equal to about 25 o'clock (15 hours of wakefulness + 10 hours of sleep), which almost corresponded to a normal rhythm. Then, over the next month, his body followed the rhythm to the duration of about 48 hours (34 hours of wakefulness and 14 hours of sleep).

The following months were surprised again: the rhythm of the measure became non-permanent and hesitated from 18 to 35 hours, with periods of activity from 12 to 20 hours and sleep from 7 to 15 hours. Sometimes he slept even 17 hours!

This irregularity of the rhythm (cycles were recorded without any rest for about 50 hours at an average duration of 25 hours) is still the interest of specialists. This is undoubtedly one of the most important results of the Experiment of Jean Pierre Meret.

3) in 1968-1969 - Voluntary imprisonment Philip Engelder and Jacques Shabra (4.5 months).

The first volunteer (Philip Engelender, 30 years old) was supposed to live 2 months with 48-hour daysand the second (Shabra, 28 years) had to live 3 months with constantly burning bright electric light (500 W).

Philip Entender:

the usual 24-hour rhythm near Philip Engender 2 weeks after the start of the experiment, the 48-hour has been replaced independently, which continued 12 days. Then, according to plan, compiled in conjunction with French military experts, an attempt was made to consolidate this spontaneously 48-hour cycle for another 2 months and achieve this with a bright lamp of 500 W, which should burn over its transparent tent for 34 hours all days. Of course, Phillippa was not known how long this lamp would burn every time.

The attempt succeeded as it is impossible. For the first time man lived in the world, where the day lengthened twice: 36 hours of wakefulness and only 12 hours of sleep, without any disturbances. Philip, as shown by numerous electroencephalograms of his sleep, perfectly adapted to this regime.

At the end, Philip provided the opportunity to live at their discretion, as in initial period experiment. There was something amazing for researchers. Philip, instead of returning to 24-hour daily rhythm, continued without the slightest effort to keep 48-hour rhythm wakefulness and sleep. So when he was announced that for January 4, he exclaimed:

Wow! I missed New Year! I thought that now only the beginning of November!

Jacques Shaber:

Jacques, as opposed to Phillippa, retained a biological account of the time close to the real day: the intervals between his awakening were average 28 o'clock. The inclusion of bright lighting had to the soul; His sleep was not at all violated. Only on the third month of the complete loneliness of his day were 48 hours, which was accompanied by enhanced physical activity (in particular, during this period he conducted intensive intelligence in the cave).

Subjectively for Jacques between its descent and access to the surface passed 105 days instead of real 130 days. Before the experiment, Jacques something read on the topic of determining the true duration of time, so it was better oriented among the past days than the neighbor Phillipp.

Ultimately, Jacques and Philip organisms lost and obeyed the 48-hour rhythm. He gave a big advantage: every day 2 hours have won. If an ordinary person sleeps 8 hours out of 24, then with a 48-hour rhythm to sleep enough only 12 hours out of 48.

Philip was a passionate speleologist. He explored his cave and left such lines in the diary: "Ruma, clearing, carving steps, I often exhausted my strength, working 4-5 hours without breaks" But, as they counted on the surface, it worked more than 20 hours!

The experiments of Shabra and Engelender were long-term analysis. They allowed select people capable of living in 48-hour rhythm. Michel Sifra writes that the criteria for this selection are already developed.

4) in 1972. - (6 months).

During the entire 2-month experiment, 1962, the subjective days of the siphra were close to normal and equal on average 24 o'clock 31 minutes, differing from real half an hour.

In 1972, as opposed to this, the subjective day increased significantly more: during the first 1.5 months each day was longer than 2 real hours (26 hours).

Then, for 2 weeks, the rhythm of wakefulness and sleep was non-permanent: 48-hour days alternated with 28-hour (their average duration was 37 hours).

Thus, in 1962, the Sifer was needed 9.5 hours of sleepto be cheerful for 15 hours; And in 1972 he had enough 7.5 hours of sleep With 28 hours of wakefulness.

Then, for several months, the cycle was close to 28 o'clock, after which this rhythm became secondary by 2 days, but without regularity: 48-hour days were alternating with 28-hour twisted. Finally, until the very end of the experiment, he stabilized at 28 o'clock.

Michel Sifre was also fluent in sensors, including those measuring rectal body temperature (In the rectum). The analysis showed that it was before the descent in the cave minimal at 2 am (1.5 hours after falling asleep). In the cave, the temperature of the temperature each time came about 1 hour later - at 3, 4 and 5 o'clock in the morning, etc., so after 2 weeks "out of time" the minimum value appeared on the curve at 3 o'clock in the afternoon. And so happened during the experiment several times.

These results for 10 years received a group of researchers led by Michel Sifrom. No one of the speleologists the day was not shortened. All of them just lengthened. Maybe this is the desire of students to go to bed in the morning, and at night awake?

Speaking about optimal daily biorhythms, it is impossible not to remember Leonardo da Vinci. It is said that he slept only 1.5 hours a day. The secret of his huge performance is that he flooded for 15 minutes every 4 hours.

Melatonin

In the human body produces a special hormone melatoninwhich is responsible for adapting to biorhythms and floating. Melatonin is produced epiphysis (sidewinded body) And improves sleep quality, reduces the frequency of attacks of headaches, dizziness, increases the mood. It accelerates falling asleep, reduces the number of night awakens, improves the well-being after morning awakening, does not cause sensations of lethargy, breaking and fatigue during awakening. Makes dreams brighter and emotionally saturated. Adapts the body to a rapid change of time zones, reduces stressful reactions, adjusts the neuroendocrine functions. Indeed immunostimulating and antioxidant properties.

Most of all melatonin is formed in the dark, excess light for it is destroyed. At night, 70% of daily melatonin is formed.

Exist preparations Melatonin For receiving inside. In Belarus sold Melaxen and Vita Melatonin. They are prescribed desynchronoz (Violation of a normal circadian rhythm, for example, with flights between different time zones), sleep disorders, depression. Preparations are not the cheapest, but, in principle, are available at the price.

(The last part of the article about the influence of the lunar cycles on miners and the Montaoughan experiment over time was removed on January 30, 2016 at the request of readers as a pseudo-native)